The invention relates to compounds which inhibit tyrosine kinase enzymes, compositions which contain tyrosine kinase inhibiting compounds and methods of using inhibitors of tyrosine kinase enzymes to treat diseases which are characterized by an overexpression or upregulation of tyrosine kinase activity such as cancer, diabetes, restenosis, arteriosclerosis, psoriasis, Alzheimer's disease, angiogenic diseases and immunologic disorders (Powis, G.; Workman P. Signaling Targets For The Development of Cancer Drugs. Anti-Cancer Drug Design (1994), 9: 263-277; Merenmies, J.; Parada, L. F.; Henkemeyer, M. Receptor Tyrosine Kinase Signaling in Vascular Development. Cell Growth Differ (1997) 8: 3-10; Shawver, L. K.; Lipsosn, K. E.; Fong, T. A. T.; McMahon, G.; Plowman, G. D.; Strawn, L. M. Receptor Tyrosine Kinases As Targets For Inhibition of Angiogenesis. Drug Discovery Today (1997) 2: 50-63; all herein incorporated by reference).
Tyrosine kinases play a critical role in signal transduction for several cellular functions including cell proliferation, carcinogenesis, apoptosis, and cell differentiation. Inhibitors of these enzymes are useful for the treatment or prevention of proliferative diseases which are dependent on these enzymes. Strong epidemiologic evidence suggests that the overexpression or activation of receptor protein tyrosine kinases leading to constitutive mitogenic signaling is an important factor in a growing number of human malignancies. Tyrosine kinases that have been implicated in these processes include Abl, CDK's, EGF, EMT, FGF, FAK, Flk-1/KDR, Flt-3, GSK-3, GSKbeta-3, HER-2, IGF-1R, IR, Jak2, LCK, MET, PDGF, Src, Tie-2, TrkA, TrkB and VEGF. Hence, there is an ongoing need to investigate novel compounds that can be used to regulate or inhibit tyrosine kinase enzymes.
It is also desirable and preferable to find compounds with advantageous and improved characteristics in one or more of the following categories, which are given as examples and are not intended to be limiting: (a) pharmacokinetic properties, including oral bioavailability; (b) pharmaceutical properties; (c) dosage requirements; (d) factors which decrease blood concentration peak-to-trough characteristics; (e) factors that increase the concentration of active drug at the receptor; (f) factors that decrease the liability for clinical drug-drug interactions; (g) factors that decrease the potential for adverse side-effects; and (h) factors that improve manufacturing costs or feasibility.